Holonomic drive

[Sugapes] always wanted to cut a few corners and build a really, really cheap 3D printer, but the idea of using linear actuators – pricing them, sourcing them, and the inevitable problems associated with them – scared him away. One day, he realized that moving in a plane in the X and Y dimensions wasn’t hard at all; cars and robots do this every day. Instead of moving a 3D printer bed around with rods and pulleys, [Sugapes] is moving his 3D printer around with wheels. It’s different, it’s interesting, and it’s the perfect project to show of his creativity for The Hackaday Prize.

The drive system [Sugapes] is using is called a holonomic drive system. In his build, three omnidirectional wheels are attached to continuous rotation servos, each of them mounted 120 degrees apart. The print bed is simply placed on these wheels, and with the right control algorithms, [Sugapes] can move the bed in the X and Y axes. With an extruder on a Z axis above the bed, this setup becomes a 3D printer with a theoretically unlimited XY build axis. Pretty clever, huh?

There are a few problems [Sugapes] will have to overcome to turn this project into a proper printer. The omnidirectional wheels aren’t the best at transferring movement to the bed, so a quartet of USB optical computer mice are being used for a closed loop system. [Sugapes] put up a video of his project, you can check that out below.

The project featured in this post is an entry in The Hackaday Prize. Build something awesome and win a trip to space or hundreds of other prizes.

Like all of us, [Jonathan Guberman] has a list of projects and builds that ‘will get done when I have time.’ His Kiwi drive robot is no exception. It’s intended to be one piece of a much larger project, but he decided to document it anyway (we think in the hope of getting is rear in gear).

The robot uses a holonomic drive to get around. A holonomic drive uses three fixed wheels placed 120 degrees apart. The wheels can be independently controlled and with some vector addition the robot can move in any direction and rotate 360º inside its own wheelbase. Of course the wheels will have to be able to roll in two dimensions, so an omniwheel is used. Everything is controlled with a Wiimote nunchuck, and the movement is very smooth.

[Jonathan] has had a few projects featured on Hack A Day before, like his Mechanical Pac-Man and his adorablePortal turret plushie. [Jonathan] really demonstrates his artistry and skill in his project, so we’re really wondering what his ‘larger project’ actually is. Take a guess in the comments section, that might get [Jonathan]’s rear in gear.